Capsules

Benefit of Defibrillators in Public Places Downplayed

Making defibrillators widely available in public places would seem to improve the chances of saving the lives of people having heart attacks.

But a new study done in Scotland concludes that wide distribution of the devices, which shock the heart back into normal rhythm, wouldn't make much of a dent in cardiac arrest fatalities. The main reason, report the researchers, is that most cardiac arrests occur at home. Among the 15,000 people in their study, only 3% had cardiac arrests in sites that are considered suitable for public-access defibrillators, such as sports centers, bus terminals and hotels.

The researchers predicted that putting defibrillators in these "suitable sites" would increase the number of cardiac arrest survivors from the present 5% to only 6.3%. If the devices were also available in "possibly suitable" sites, such as on buses and in parking garages, the survival rate would increase slightly to 6.5%.

"It's important to realize that wide availability [of defibrillators] is but one tool to improve ... survival," says Dr. Vinay Nadkarni, the chairman of the American Heart Assn.'s Emergency Cardiovascular Care Committee. "We can make a small impact with the technology, but a large impact will require training people on the whole chain of survival." That chain includes recognizing signs of a heart problem, using the defibrillator or performing CPR and, of course, prompt arrival of the paramedics. British Medical Journal 325: 503-504, 515-520.

An Alternative to Tamoxifen Wins Approval From FDA

Post-menopausal women with breast cancer often take tamoxifen, which blocks the tumor-fueling effects of female hormones but can raise the risk of uterine cancer. Now they have another choice.

Early this month, the Food and Drug Administration approved the drug Arimidex (anastrozole) for treatment of early-stage, hormone-sensitive cancer in such women. The drug, which blocks the production of estrogen, had previously been approved for more advanced cancer.

The new approval was based on a trial involving 9,300 women in 21 countries. That study found that Arimidex alone was slightly more effective than tamoxifen in preventing recurrence in early-stage cancer patients who had undergone surgery. Although the study followed women for just 31 months, the results indicate that Arimidex had fewer side effects, such as vaginal bleeding and hot flashes, and was safer than tamoxifen, says Dr. Aman Buzdar, professor of breast medical oncology at the University of Texas M.D. Anderson Cancer Center in Houston.

However, an American Society of Clinical Oncology panel raised cautions in May about the lack of long-term follow-up. One disadvantage of Arimidex is that it doesn't prevent bone loss as tamoxifen does. Dr. Jennifer Malin, assistant professor of medicine at UCLA and a researcher at the UCLA Jonsson Cancer Center, says, "It's too early to say that Arimidex will replace tamoxifen.... It looks like it has a slightly lower risk of uterine cancer, but we don't know what the long-term side effects might be."

For now, Malin says, "The only role I see [for Arimidex] is for post-menopausal women who for some reason can't tolerate tamoxifen."

Avoiding Milk Has Major Impact on Children's Bone Growth

Countless studies have shown that calcium is essential for healthy bone growth, and every parent knows that milk is an excellent source of the mineral. Now the first study of bone development in healthy children who have avoided milk has shown the impact of that deficiency.

New Zealand researchers at Otago University found that children who didn't drink milk were shorter and their bones were smaller and more fragile than those who drank it regularly. The bone mineral density of those who avoided milk was 7% lower than that of children in the control group, and some children were 20% below normal. A high proportion of the boys and girls, ages 3 to 10, had already experienced broken bones. On average, the milk avoiders were about 2.4 inches shorter than the milk drinkers.

Although past research had shown that children who are allergic to milk or lactose intolerant have low calcium levels, no studies had evaluated as many bone measurements in healthy children who deliberately avoid milk.

The researchers also discovered that few of the chronic milk avoiders drank calcium-rich substitute drinks or took supplements.

American Journal of Clinical Nutrition 2002; 76: 675-80

High 'Empty Calorie' Consumption May Predict Weight Gain

While many of us are counting calories and fat grams to control our weight, new research shows that the overall pattern of what you eat is an important predictor of weight trouble.

Using detailed food questionnaires, Boston University researchers categorized the eating behavior of about 700 normal-weight women. Of the five categories, the women who were most likely to be overweight in the following decade or so were those who tended to eat more empty calories, foods with a lot of calories but little nutrition.